Stressed metal devices have become increasingly important for fabricating interconnects, probes, inductors and the like. However, fabrication of the stressed metal devices is a difficult and expensive process. One reason for the extra expense is the use of multiple lithography steps.
Prior art spring formation techniques typically use at least two lithography operations. A first lithography operation patterns a stressed or bimorph metal to form a general spring structure. A second lithography operation defines a spring release area (the release area is defined as the region that uplifts from a substrate). The second lithography operation may also be used to plate additional metal onto the stressed metal spring. A detailed description of the entire process is provided in U.S. Pat. No. 6,528,350 which is hereby incorporated by reference in its entirety.
These two basic lithographic operations have remained the same for about ten years. The cost associated with two lithographic operations has kept spring interconnect technology more expensive then some competing interconnect technologies. Thus a more efficient and thus less expensive way of fabricating a stressed metal device is needed.